Secret Passage
by Marvelle Petit
Summary: FE3H: Byleth finds a secret passage in the library. Thinking she was alone, she decides to see where the passage leads... F!Byleth/Claude; One-shot; No spoilers/general pre-timeskip timeline


_Look above you, on the fifth shelf. There is a peculiar book. I wish to read it._

Of all the books on the fifth shelf, none seemed peculiar to Byleth. Most books on this bookcase were far before her time and used an ancient form of dialect that was difficult to read. Sothis understood it perfectly, but she didn't read any of it aloud and simply commanded _turn the page_.

Reading aloud was a pain, she knew that from teaching, but to reduce someone to a page-turner and then become offended when they fell asleep was a bit much, no?

Still, if she picked the wrong book Sothis would have a snappy remark of how she picked a pedestrian book compared to the obviously outlandish book requested and Byleth did not want to hear it, especially since she couldn't argue with Sothis in a public place, especially one as quiet as a library. Even though it was empty now, that didn't mean that someone couldn't walk in. Not to mention Seteth's office was on the same floor and he had a way of catching her in compromising situations.

Ever since students from other houses began requesting to join hers in droves both the class size and student squabbles became more difficult to manage. Any sort of assignment requiring teamwork led to drama and considering nearly everything they did required teamwork…

Claude especially annoyed her. Depending on his mood, he either aided her by saying a barb of a line that quieted the disagreement or made it worse by tossing wood into the fire. On more than one occasion she thought it would have been better to join Dimitri or Edelgard's house who seemed more responsible and less likely to disrupt order for personal entertainment.

In short, she was exhausted, but Sothis insisted there was a book in the library that could give a hint about their connection and shared past and now she stared at a row of books, playing spot the difference when Sothis should have given a clear command such as, third book from the right.

There weren't many differences between them. Some used similar leathers to bind them. Some had gold lettering that faded somewhat. Some had silver. The titles on the spines made no difference to her. She could only read a few of them anyway and the ones she could read were about the church. Boring.

_What's taking you so long?_ Sothis snapped.

Byleth reached up and grabbed a random book.

_No, not that one, you fool!_

But there was something behind that book.

A small switch.

Sothis continued ranting, oblivious to the switch until Byleth pushed it and the bookcase clicked, rotating sideways.

A hidden door.

As old as the monastery was, there had to be a multitude of secret passages and corridors. Byleth couldn't keep the smile from her face.

_My, my, what have you found? _Sothis asked, voice playful and curious. Whatever interested her about the book was gone; they were fully in tune. The corridor looked pitch black, however. They needed a torch. _Hurry! I must know what's down there!_ Sothis prodded.

She didn't have to tell her twice. Byleth put the book back and carefully locked the bookcase back into place.

Would it be perfunctory to bring a sword as well? She walked back to her room at a slightly faster pace than usual. A sword might be overkill, but at this point, a sentient ghost guarding a secret chamber of some sorts seemed perfectly possible.

She grabbed a couple of torches, an elixir, and her sword.

_A bit much, don't you think?_

"It seems like every time we do something simple around here it turns into something crazy."

Sothis chuckled. _You have a point._

She patted her sides and did a quick spin. Hopefully, they didn't add too much bulk. Those students of hers were known to follow her with no regard to whether or not she needed alone time. All it took was one to see the glint of a sword or the outline of a torch to spy and gather the crew to follow. Why couldn't they have great teamwork like that during lessons?

Thankfully, the library was still empty when she returned. She pulled the book out, hit the switch, and slipped through the door. After lighting the torch she shut it behind her and began walking downstairs.

The stairs were long and winding. She tried to visualize them in respect to the building and figured they lead down to beyond the base level to a basement. Interesting.

A loud thud echoed behind her. She turned around and saw nothing.

_You know how these old places speak. It is nothing. Keep going!_

Finally, she came upon a door. It was made of wood that saw better days and had rusted iron hinges. She grasped the handle and pulled. It didn't budge. She groaned and tried again, tugging hard. Still, nothing.

_It's so old you can probably kick it down._

"I don't want to clean up the mess."

She set the torch down on the stone steps and grasped the handle with both hands, braced her legs, and pushed, ramming her shoulder into the door.

Something popped and the door swung open, sending her flying into the room. She landed on her knees and took a mouthful of dust. She spat out and coughed.

_What a filthy room. I wonder how long it's been undisturbed?_

Byleth shrugged. She stood up and dusted herself off as best she could. When she turned around to fetch the torch, she yelped.

Claude held up the torch, smiling with that devilish grin of his. "Looking for this?" He chuckled and stepped into the room. "Not too often I get the upper hand. I rather liked that little noise you made. Do it again?"

She rolled her eyes. "Give me the torch."

"So, how did you find out about this place?" Claude asked, ignoring her request. "Looks great. A real relic of lost to time."

It seemed to be some sort of bedroom or living quarters. There was a bed in the corner. A shelf with several books, though mostly empty. A couple of seating chairs with a small table between them. A desk with dried ink wells, broken quills, and crumbly parchment. A two-seater dining table with a pink teapot and a three-tiered dessert stand. There was even a bathroom. She turned the faucet. Black water spewed out. She wrinkled her nose. "That smells disgusting."

"Let it run, it'll become clear soon enough." Claude pulled dead flowers from a crystal vase and set the torch inside. "What do you think it was used for? Rather out of the way for a simple bedroom, don't you think?"

She shrugged. "I don't know enough of the monastery's history to know why they would need a hidden room."

He smirked. "Think it's a secret love den for the archbishop?"

"In this state?"

"Why not? Everyone has needs, you know."

"Lady Rhea would never."

He shrugged. "Maybe she just doesn't use this place but in the past someone did."

_How disappointing._ Sothis drawled. _I hoped for something more interesting. _She yawned. _I'm going to rest. Have fun with your little deer._

"Why don't we clean it up and make it our little secret meeting place?"

"_Our_ meeting place?"

He put his hands behind his head and sauntered over to her. "Yes, _our_ meeting place. Come on, teach, I know you have needs too. It has everything we need for a good time."

She knew enough about Claude to recognize when he was trying to get a rise out of her. He seemed to relish when he could break her poker face. This time it was too obvious. "Enough," she replied in a stern tone.

His eyebrow raised and he cocked his head to the side, long braid swaying lazily. "You want to do it that way? The naughty student and the stern professor?"

"Claude," Byleth snapped.

He laughed. "I'm kidding, don't make that face at me." He pulled a book off the shelf and opened it up, flipping through the pages. "I was serious about cleaning this place up. Looks perfect for when you need some time alone to think."

That was true. Having a place to be alone for a few hours sounded lovely. Claude was the only one who knew about this place anyway and it was unlikely they would both think to come to the room at the same time.

"Think if we tell Cyril that Lady Rhea wants to use it he'll clean it up for us?"

"Quiet, Hilda."

Claude chuckled and shut the book. "I think I'll be taking this back up with me."

She picked up a half-melted candle. "It hasn't been used in so long they don't even have lanterns."

"We should keep it that way. Set the mood."

"Set it on fire, more like." She picked up the torch. "Coming back upstairs?"

"Going to get cleaning supplies?"

She said nothing in reply and turned, knowing he'd follow behind her.

* * *

Despite longing to go to the secret room, Byleth had so many things on her plate she lacked the time to go there. The past three weeks it lurked in the back of her mind, taunting her. The first day they discovered it, her and Claude spent the night tidying it up and restoring it to a usable condition.

But after walking a scared Lysithea back to the dorms after a tutoring session, she thought to turn around and visit the secret room. It was late at night. There shouldn't be anyone in the library or any student to bother her. The night owls of the academy were few and far between.

Granted, Claude was one of those night owls, but she would take her chances. He was one to wander, not hole himself up in a single room.

"Evening, teach. Can't sleep?" Claude greeted as she entered the room.

What were the odds?

Claude sat sideways on the seating chair, one leg draped over the armrest, book in hand.

"I have some tea over there. It's an Almyran blend. You'll like it."

With a restrained sigh, she walked over to the teapot and poured herself a cup.

"You know, the books here are very interesting."

"Are they?"

He swung his leg off the armrest and stood up, shutting the book with a loud thump. "I think I know where an ancient weapon cache is now. Want to go investigate next weekend?"

"Sure." She took a sip. Her brows arched. Delicious! Spicy and sweet, but not in the way the Fodlan teas were sweet. This one had a sort of richness the other teas didn't possess.

He gave her a lazy smile. "Like it?"

"Someone from home sent you a care package?"

For a split-second, his eyes widened. But it only lasted a heartbeat and he put his hands behind his head in that carefree way he did when he wanted to play something off as casual. Surely he knew she already saw through that ruse of his.

"Care package? I don't even get letters."

"Is that so?"

"Drinking that tea does make me miss home, just a little. How about you? Do you have a place to call home to miss?"

She tapped her cheekbone in thought. "We were always on the move. I guess you can call this my first home."

"Do you like it here?"

"What sort of question is that?" she replied before taking another sip. Almayran blend, huh? Next time she was in the market she would have to procure some of her own. It had cinnamon in it for certain along with some other spice she couldn't quite place. The sweetness, too, had a unique feel to it. It wasn't honey.

He shrugged. "Here, everything is pretty different than where I grew up. Good and bad. I see things I want to take from both sides and sort of fuse them together into something great."

"Things are a lot calmer here," she mused. "Between my father's drinking and those rowdy men in the band, every night was loud."

"Oh really?" he took a seat across from her and stared at her with those deep eyes. "So, teach prefers quiet evenings."

"I hoped to have one tonight," she replied before taking a small sip of tea.

He put his hand on his chest in mock indignation. "Me? Loud?"

She put on a small smile. "Do you ever shut up?"

He returned her smile. "If I'm quiet until you say it's okay to not be, will you give me a reward?"

That sweet tone could rope anyone in, and part of her hated that she wasn't entirely immune. Still, she didn't have the heart to outright shoot it down. Whatever he wanted was probably minor and she would get her quiet evening in exchange. "What do you want?"

"How about I tell you after I earn it?"

That could only mean he wanted something that skirted on the side of her saying _no_. "If it's too outlandish I will refuse."

His eyes seemed to twinkle. Big mistake. She should have just outright refused. He sauntered over to the reading chair, lounging on it like a lazy cat, and opened his book.

She poured herself another cup of tea. The lamp on the table bathed him in a gentle golden glow. When he turned the page of the book, he did it with his middle finger instead of his index. It was rather strange, yet, something she wouldn't have noticed if they weren't in this room together. She imagined no one else would probably ever notice. She restrained a sigh. What was she doing, watching someone read?

She stood and stared at the tea and the desk. If she went to the desk, her back would be against Claude. That might be a bad idea. He would attempt to catch her off guard. He already tried to scare her four times since they discovered the room, because, quote, _I want to hear that cute noise again._ She grabbed a sheet of parchment along with a quill and small inkwell and took them back to the small dining table. Despite wanting an evening not thinking about the academy or her responsibilities, in quiet moments her mind wandered to teaching and becoming a better mentor.

Tomorrow they would study magic-fighter formations and she needed to figure out who would work best together. She stupidly put Felix and Sylvain together yesterday for horseback training, thinking the childhood friends would be easy-going and Sylvain would be able to teach Felix a lot but discovered they were a bickering pair of fools. Maybe Dorthea would be a good pair with Sylvain. She seemed mature enough to not become enraptured in Sylvain's flirtatious attitude.

Claude was flirtatious too, but in a different way than Sylvain. She tapped her cheekbone. What was it exactly that made him so different? Sylvain's lines were a joke, but the same thing from Claude's mouth had a chance of triggering some sort of internal response she had to shut down before it broke her façade. Both boys were equally handsome and had an equal amount of admirers. Claude never seemed to partake in any relationships, though. He seemed to flirt and provoke but never actually take the final steps to a relationship. How curious.

The crinkle of page interrupted her thoughts. He really was being quiet. She could scarcely believe it. What sort of reward would he want? With Claude, it could truly be anything. He could tease her and want something silly or he could be serious and want an actual favor.

_I see; a quiet evening to you entails staring at your favorite student. _Sothis interjected.

Byleth pursed her lips and scribbled a response on the parchment. _I don't have favorites and you know it._

_I am a part of you, you know. I can feel everything._

_Then you should feel my discontent and go back to sleep._

Sothis yawned in that blasé way of hers. _Fine. Don't do anything you'll regret._

Whatever. Byleth continued working on grouping the fighters and mages together. The white mages weren't as powerful, so they needed the stronger physical fighters that could help finish what they started. Mercedes got along with everyone easily but Marienne would shut down if she was placed with the wrong people…

Satisfied with the groupings, she rolled up the parchment and placed it into her inside jacket pocket. She took the empty teapot and rinsed it out in the sink before walking over to the chair. "Thank you."

He smiled. "Was I a good boy?"

There he goes again. "What did you want as a reward?"

He returned his gaze to the book and turned the page. "You know, while I was reading, I had a thought. This place really does feel like its own little world, doesn't it? You can't hear the normal sounds of the monastery. It's like we've stepped into an uncharted land, just the two of us."

Where was he going with this?

"And then I thought, I've seen a lot of sides of you, Teach. But there's one I really want to see that I haven't had a chance to."

"What does this have to do with your reward?"

He shut the book and stood up. "Everything. We're pretty much secluded in here, right? There's no chance of anyone coming in or anyone seeing us. We can do anything we want here and know that unless one of us mentions it, it won't ever be known."

Her chest tightened. "I'm not sure I like where this is going."

He chuckled. "I don't want anything big from you. I've seen plenty of your different faces, but the only one I haven't seen is your blushing one."

"My blushing face?" she stammered. "What do you mean?"

"My reward. I want to see what you look like when your cheeks are red."

"That's not exactly something I can do on command."

He nodded. "True. But will you give me that as my reward?"

She wrinkled her brows. "How exactly would I do that?"

"What do you say?"

"I'm not sure what to say to that."

"Yes or no."

She shrugged her shoulders. "I guess so…"

He smiled. "Good. Then I'll do my best to make you blush."

Her stomach knotted. She got caught up in one of his schemes. If Sothis were awake, she'd surely scream _You fool!_

"I changed my mind. Pick something else."

Claude ticked his tongue. "Not very noble of you to go back on your word like that."

"I'm not a noble."

He laughed. "I haven't even told you what I want to do."

Her breath hitched. "I'm not sure I want to know."

"Is it really so bad, hmm?" he took a step towards her, closing the small gap between them. "There are two ways to make someone blush. One, embarrass them. Two…" he trailed off, cupping her chin with his hand.

"This is a bad idea."

"It is?" He lifted her chin up. "I don't think it is."

"Stop teasing me. That's not going to make me blush."

"Who said I was teasing?"

"No man with intention takes that long."

He gave her that lazy smile, the one he did when he was being mischievous and wanted to charm his way out of it. "You're saying if I had intention, you wouldn't object?"

"That's not what I'm saying at all."

"I thought this would really work. Guess I have to try plan B."

"Plan B?"

He kissed her.

She had every opportunity to push him away.

But she didn't move.

It wasn't her first kiss. She had a couple of secret boyfriends (if Jeralt knew the poor boys would be in for a world of hurt) during her time as a mercenary.

But this felt entirely different.

This sent tingles through her body. This tasted of warm spices and sweet taboo. He was her student. She shouldn't be kissing a student, no matter if they were the same age.

His arm wrapped around her waist, tugging her closer to him.

She still didn't push him away.

When his lips deepened the kiss, she followed his lead. Was he practiced or was he just a natural?

Her tongue was the first to demand entrance through his lips. It was wrong, so wrong, but if they only had one kiss to share, she wanted to feel every nook and cranny of his delicious mouth. A deep moan rumbled in his throat. She grew bolder, tangling her fingers in those soft curls of his, pressing his mouth to hers.

His rough hand slid down her back to her leg, lifting it up and around his back. No, that was too dangerous. She could handle a kiss, but their hips touching, feeling _that_ part of him, the danger inherent crept too close to a line she couldn't cross.

Just a little longer, she reasoned with herself. She was still the one in control. Despite wanting to grind her hips into him, tease him the way he always teased her, bring him to the edge and never letting him truly cross it, she knew she couldn't. That was reserved for lovers. Lovers were of equal standing. Not students.

A kiss already crossed the line of depravity, but the goalpost already moved. Kissing was one thing. Intimacy was another. They could share one kiss. Her body protested the notion. She didn't want just one kiss. She wanted hundreds. Thousands, even. If this was their own little world, could she use her power to keep them infinitely entangled, an eternity of bliss.

Their kisses began to reflect their hunger. His hands cupped her buttocks, squeezing them, pressing her into his hips. Heat spread from her core through her body. A moan caught in her throat as he rubbed against her in a steady rhythm.

"Claude," she breathed. "We shouldn't."

"The hell we shouldn't," he grunted, lifting her up and pushing her to the bed. Now she felt the entirety of him pressed against her, turning her body into goo. Who cares if she crossed a line? They both wanted it. They both risked their lives day in and day out. They could die the next mission. Who cares if they indulged in each other for one night? She reached for the zipper of his jacket and pulled it down. He shrugged it off and took off his yellow undershirt. His lean muscles were marred with tiny scars of battle. Far too many for a noble child. She had her shares of battle scars, but she was a mercenary. That was expected.

Just where exactly did he come from?

She ran her fingers over his scars, gazing up at him, questioning their origin. He shook his head and brushed her hand aside, kissing her with a desperate intensity. No, this wasn't right. They were slaves to their passion. It felt good, yes, but it wasn't a connection beyond surface level.

She broke their kiss. "We can't!"

He pressed his forehead against hers, taking deep shaking breaths.

She stroked his deep curls. "We can't," she whispered.

He said nothing in reply.

She reached up and cupped his cheek, stroking his cheekbones with her thumb. "I'm sorry."

His eyes clouded and his brows furrowed. "Why—"

Time rewound around her. There was no way they could ever return to normal after this. Sleeping with him would cure their hormonal urges but it would forever blackout any hope of reaching the loneliness in the depths of his gaze. She had yet to see his smile reach his eyes. And she wouldn't ever see that if they fell into their lust before trust. She needed the wall between teacher and student to exist. And, someday, perhaps, they would do this again. And she will know the story of those scars on his body, the loneliness of his gaze would be gone, and they would completely trust each other.

"Plan B?"

He leaned down to kiss her.

She held up a single finger over her lips, blocking his advance. "You know better."

He laughed. "You got me." He released her chin and picked up the book he was reading. "Guess it's time to go back to our real beds, huh?"

She nodded.

As she turned to leave, he grabbed her hand. "Byleth."

He never used that dulcet tone of voice before. Hearing her name in such a manner sent shivers through her core. Her face became hot. She turned, eyes wide. "Did you just call me-?"

He grinned. "Only show that expression to me."


End file.
